Studied by 3 people
3 properties of solids
strong forces of attraction, vibrate, regular lattice
2 properties of liquids
weak forces of attraction, move freely
2 properties of gases
very weak forces of attraction, move very freely
what happens to particles during melting, boiling and sublimation?
move faster, weakening the forces
what happens to particles during condensing, freezing and sublimation?
move slower so get closer
what is boiling?
all particles move at the same speed so all turn into gas at the same time
what is evaporation?
some particles move faster so they turn into gas first
experiment of dilution
crystals of potassium manganate in water
experiment of diffusion
bromine gas and air
what is a solvent?
The liquid in which the solute dissolves
what is a solute?
A substance that is dissolved in a solution
what is a solution?
the mixture formed when a solute dissolves in a solvent
what is a saturated solution?
a solution where there is an equilibrium between the solution and its solute
What does soluble mean?
able to be dissolved
what does insoluble mean?
unable to dissolve
as temperature increases, gases become .......... soluble
less
as temperature increases, solids become ........... soluble
more
as pressure increases, gases become ........... soluble
more
What do solubility curves show?
solubility in g per 100g of water against temperature
what is an element?
a substance of only one atom, which cannot be split
what is a compound?
pure substance of two or more elements chemically combined, which cannot be separated physically
what is a mixture?
a combination of two or more elements not chemically combined, which can be separated physically
What are pure substances?
fixed melting and boiling points
what are mixtures?
melt and boil over a range of temperatures
what is simple distillation used for?
Separating a liquid from a solution
simple distillation can only be used to separate substances with ........ ................... boiling points
very different
what is fractional distillation used for?
separating a mixture of liquids
what is filtration used for?
Separating an insoluble solid from a liquid
What is the retention factor in chromatography?
distance travelled by dye/distance travelled by solvent
what is crystallisation used for?
Separating a soluble solid from a solution
what is an atom?
Smallest particle of an element
what is a molecule?
smallest part of an element or compound that can exist independently
what does the nucleus contain?
protons and neutrons
where is the main mass of an atom?
nucleus
mass and charge of proton
1, +1
mass and charge of neutron
1, 0
mass and charge of electron
1/2000, -1
if an atom is neutral, number of ............ = number of .............
protons, electrons
what is relative atomic mass?
average mass of the isotopes of an element
how do calculate relative atomic mass?
number of neutrons (mass number - atomic number)
what are molecules held together by?
covalent bonds
what are isotopes?
atoms of the same element with the same number of protons but different numbers of neutrons
what is the period?
horizontal row showing number of shells
what is the group?
column showing number of outer electrons
are metals alkaline or acidic?
alkaline
are non-metals alkaline or acidic?
acidic
what are the chemical properties of elements in the same group like?
similar
the noble gases are ............. because they have a ........ ............. ............
unreactive, full outer shell
what are moles?
amount of a substance
moles =
Mass / Mr
how do you calculate reacting masses?
find moles, ratio, moles of other substance, apply this answer to find mass
what is percentage yield?
The amount of product you get
percentage yield =
actual yield/theoretical yield x 100
what is the empirical formula?
The simplest whole number ratio of atoms of each element in a compound
what is the molecular formula?
exact number of atoms of each element in a compound
what is ionic bonding?
bond between a metal and non-metal with strong electrostatic forces of attraction between oppositely charged ions
ionically bonded substances have ........... melting and boiling points
high
charge of group 1
+1
charge of group 2
+2
charge of group 3
+3
charge of group 5
3-
charge of group 6
2-
charge of group 7
1-
silver ion
Ag+
copper charge
Cu2+
iron charge
Fe2+
lead charge
Pb2+
zinc charge
Zn2+
hydroxide charge
OH-
ammonium charge
NH4+
carbonate charge
CO32-
nitrate charge
NO3-
sulphate charge
SO42-
what are giant ionic lattices?
giant three-dimensional lattice structure held together by the strong attraction between oppositely charged ions
do giant ionic lattices have a high or low melting and boiling point?
high
Can ionic compounds conduct electricity?
when they are not solids
what is covalent bonding?
the bond between two non-metals formed by a shared pair of electrons between the atoms
what are electrostatic attractions in?
covalent bonding
what are electrostatic attractions?
the strong attraction between the shared pair of electrons and the nuclei involved
what is a simple molecular structure?
consists of molecules in which the atoms are joined by strong covalent bonds
Why do simple molecules have low melting points and boiling points?
they have very strong covalent bonds between atoms but weak intermolecular forces
what is relative molecular mass?
total relative atomic masses form all atoms shown in its chemical formula
which is giant covalent structure?
contains lots of non-metal atoms, each joined to adjacent atoms by covalent bonds forming a giant lattice
giant covalent structures are.....
solids
giant covalent structures have .......... melting and boiling points because ............
high, strong covalent bonds
what are allotropes?
different atomic and molecular arrangements of the same element
why is diamond hard?
each carbon atom is joined to 4 other carbon atoms with strong covalent bonds
Why does diamond have a high melting point?
giant covalent structure means that there are lots of strong covalent bonds
Why does diamond not conduct electricity?
all outer shell electrons are used in covalent bonds, there are no delocalised electrons to conduct electricity
2 uses of diamond
cutting tools, jewellery
why is graphite soft and slippery?
made up of layers of carbon atoms held together which have weak forces of attraction between them
Why does graphite have a high melting point?
each carbon atom has strong covalent bonds with the three other carbon atoms in a giant covalent structure
Why does graphite conduct electricity?
only three electrons are used in the covalent bonds, the fourth electron is delocalised and free to move
2 uses of graphite
lubricant, electrodes for electrolysis
why is C60 fullerene soft?
each carbon atom is joined to three others so there are weak intermolecular forces between the molecules
why does C60 fullerene have low boiling points?
each carbon atom is joined to three others so there are weak intermolecular forces between the molecules
why do covalent compounds not conduct electricity?
they don't have any delocalised electrons that are free to move and conduct charge
what is a metallic lattice?
giant three-dimensional lattice structure of positive ions surrounds by a sea of delocalised electrons
How are metal atoms held together?
metallic bonding
what is the sea of delocalised electrons in a metallic lattice?
when the metal atoms lose electrons to become ions
Note 
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